Experience letter and salary matter

Dear Sir, I Join a company in 27 Oct 1014 and I given resignation to this company on 21 Nov 2014, because I got better opportunity somewhere else. I resigned from there with 8 days requested notice period. Then they asked me am I ready to serve one month notice period. I said yes but it will not be worthfull to me and company also as I joined there hardly one month before there. Now they denied me serve even one week notice period as I requested on my resignation. And I was agree so they release me on 25 Nov 2014. Now I need my releaving letter from there to join another company. On my last day with my company k discussed about my releaving letter they just said I will get it within 45 days. But now I don't have anything in written that wheather they released me from there before my notice period or I left ... What should I do if in case I could not get my releaving letter from there. It is mandatory to me to give in next company where I am selected and my joining will be in next month. Give me a advice. Jayant kumar #9540130800